To maximize seed longevity, seeds should be harvested at optimal maturity, that is, when seeds have acquired maximum physiological quality before deterioration begins. The aim of this study was to map the variation in temporal patterns of lentil (Lens culinaris Medik.) seed quality development when grown across four regeneration environments, which differ in the level of temperature and humidity control throughout the growing season, at the Australian Grains Genebank. Seeds of two lentil accessions (76080 and 76072) were harvested at different stages throughout development, commencing at 21 d after 50% anthesis until a maximum of 130 d. At each harvest, physiological quality traits, including germinability (fresh and dried seeds) and seed longevity, were determined, as well as seed dry weight and moisture content. Seeds of both accessions, and in all environments, started to accumulate physiological quality early on in development but did not reach their maximum until 3–54 d after mass maturity. The temporal patterns of desiccation tolerance and storage longevity were highly influenced by the environmental conditions during the maturation drying phase, affecting both ‘when’ maximum quality was attained and for how long it was maintained, thereafter. Seeds did not show a typical developmental response, rather variation was observed in seed quality development both between and within accessions grown in the different environments. The poorest storage longevity was seen when seeds of both accessions were grown in the cooler, temperature-controlled glasshouse, and the maximum longevity was observed in the warmer, semi-protected environments of the green and the big igloo for accessions 76080 and 76072, respectively.

Genebanks offer vast amounts of traditional germplasm with potential sources of novel genes against biotic and abiotic stresses. In order to utilize the germplasm in rice breeding programmes, there should be a fast screening approach such as the use of molecular markers. Thus, the current study aimed to evaluate the use of tsv1 resistance-linked simple sequence repeat markers (SSR) for the preliminary screening of Philippine traditional rice germplasm against rice tungro spherical virus (RTSV). The tsv1 resistance-linked SSR markers consisted of two to four repeat motifs with 5–24 base repeats. Expected sizes ranged from 123 to 465 base pairs (bp) with polymorphism information content ranging from 0.23 to 0.73. Genetic analysis showed six major clusters at 50%: Clusters A, B and C had individual accessions, Cluster D had three accessions, Cluster E had 55 and Cluster F had 42 accessions. The study showed the germplasm with alleles linked to tsv1 but should be validated in the future with induced screening. In general, the material consisted of selected germplasm showing the presence of alleles linked to the tsv1 gene. These rice accessions could be a source of resistance to RTSV following further validation. Furthermore, molecular markers provide a useful tool to accelerate the screening of genetic resources for biotic and abiotic stress tolerance.

In each of two experiments, freshly harvested seeds of two cultivars of rice were dried and then rehydrated to different moisture levels. In experiment 1, seed equilibrium relative humidity (eRH) and moisture content (MC) were determined at each moisture level so that moisture desorption and adsorption isotherms could be constructed. Seed storage experiments were also carried out for seeds equilibrated at each moisture level, in sealed aluminium foil packets at 45°C. In experiment 2, storage experiments at 45°C were carried out on seeds dried to 12% MC and seeds dried to lower moisture levels and then rehydrated to 12% MC.

The moisture adsorption isotherm was shifted to lower MC at a given eRH compared with the desorption isotherm. This hysteresis effect was seen both when seeds were dried to <6% MC and then allowed to adsorb moisture to different levels, and when seeds were dried to different levels (10, 8, 6 or 4% MC) and then allowed to adsorb moisture up to 12% MC. The log-log relationship between seed longevity, σ [the standard deviation of the normal distribution of seed deaths over time, as defined in the Ellis and Roberts (1980) seed viability equations] and seed storage MC did not vary depending on whether the seeds were desorbing or adsorbing moisture. The relationship between σ and eRH was better described by a log-log model than a log-linear model and did vary depending on whether seeds were desorbing or adsorbing moisture: at a given eRH, the longevity of adsorbing seeds was greater than that of desorbing seeds. The implications for seed storage are discussed.

With regard to the survey data of Korean researchers using genetic resources from three genebanks administered by the Korea Research Institute of Bioscience and Biotechnology, we conducted conjoint and cluster analyses to estimate the relative importance of genetic resource (microbial, plant and animal) attributes among the researchers. Our results indicate that Korean researchers view price (cost of acquiring an accession), high new functionality (functional properties of germplasms for specific applications and uses) and completely uncovered genomic information (about mutation, genetic transformation, genomic function and pathways) as far more important in decision-making about R&D use of microbial, plant and animal genetic resources, respectively, than other attributes. Furthermore, this study shows that researchers conducting R&D in the microbial and plant genetic resource sectors especially prefer resources from specific domestic environments and Korean indigenous species, respectively. The study also sheds light on different patterns of researcher segments in terms of utilities of attributes and subgroups of researchers who have common needs in the three genetic resource sectors. We proposed some policy and strategic implications based on the results of this study.

Niche modelling software can be used to assess the probability of detecting a population of a plant species at a certain location. In this study, we used the distribution of the wild relatives of lettuce (Lactuca spp.) to investigate the applicability of Maxent species distribution models for collecting missions. Geographic origin data of genebank and herbarium specimens and climatic data of the origin locations were used as input. For Lactuca saligna, we varied the input data by omitting the specimens from different parts of the known distribution area to assess the robustness of the predicted distributions. Furthermore, we examined the accuracy of the modelling by comparing the predicted probabilities of population presence against recent expedition data for the endemic Lactuca georgica and the cosmopolitan Lactuca serriola. We found Maxent to be quite robust in its predictions, although its usefulness was higher for endemic taxa than for more widespread species. The exclusion of occurrence data from the perceived range margins of the species can result in important information about local adaptation to distinct climatic conditions. We discuss the potential for enhanced use of Maxent in germplasm collecting planning.

Cacao (Theobroma cacao L.) was domesticated in Mesoamerica and is native to the South American rainforest. Belizean Criollo is a group of relic landraces that are thought to be similar to those used by the Olmecs and Mayans during early domestication. Knowledge of genetic diversity is essential for efficient conservation and use of these relic landraces. Using 30 microsatellite markers, we characterized genetic diversity in 77 Belize Criollo accessions collected from the Maya Mountains in Belize, and assessed their relationship with 62 cacao accessions including 25 Trinitario accessions. Genetic diversity and heterozygosity were low in Belizean Criollo germplasm. Eleven distinctive genotypes were identified among the Belizean germplasm. Results of ordination and cluster analysis supported their putative ancestral contribution to the Trinitario cacao. However, results of Bayesian assignment and parentage analysis both suggested that the contribution of Criollo cacao to the Imperial College Selections Trinitario is small. Our preferred hypothesis for the genesis of Trinitario cacao is that a limited population of Criollo × Forastero hybrids emanated from the introduced Forastero population of Trinidad. The present study provides new insights into the origin of the Trinitario cacao, which will be useful in the ex situ and in situ conservation of cacao landraces from Mesoamerica.

Seed shelf-life or longevity is difficult to predict or to measure on a practical time scale. Predictive models suggest that water has the same effect on ageing rate for all seed lots within a species and that initial seed quality is the dominating factor explaining within-species variation. These assumptions are used in ‘accelerated ageing’ or ‘controlled deterioration’ (AA/CD) tests, which are commonly used to predict seed longevity in commercial and research applications. In this study, we describe within-species variation of longevity for seeds of Secale cereale and S. strictum (cultivated rye and its wild progenitor) under typical dry storage conditions of a genebank, and show that initial seed quality is an important, but not sole, factor explaining measured longevity. We also test the correlation of seed longevity, measured under humid and dry conditions, using 50 cultivars of rye, wheat (Triticum aestivum) and the intergeneric cross triticale, to assess how well AA/CD tests predict seed shelf-life during dry storage. Known differences in longevity between wheat and rye were confirmed at all water contents, and triticale seeds demonstrated intermediate behaviour. Longevity measured for humid and dry conditions were weakly correlated when comparisons included all grain types and were not correlated in within-grain-type comparisons. Response to moisture varied among cultivars. These findings do not support assumptions made in seed ageing models that use AA/CD tests. Our results suggest that more traits are involved in the expression of seed longevity than those typically measured in studies of initial seed vigour.

The ability of crop seeds to retain their viability over extended periods of uncontrolled temperature and/or relative humidity conditions has not been widely investigated, although this is an important issue for genebank management. We report here the response of 18 crop species to storage for up to 26 years at 20.3 ± 2.3°C and 50.5 ± 6.3% relative humidity. Germination rates decreased in a sigmoid fashion, but the curve parameters were species characteristic. Pea, common bean and maize seeds retained their viability over the longest period (23, 21 and 19 years, respectively). In contrast, chive seeds survived for only 5 years and lettuce for 7 years. In addition to this interspecific variability, there were also indices for intraspecific variability, particularly in bean and chive seeds, just as in collard, lupin, poppy, wheat and maize seeds. A significant correlation was obtained between germination performance in the laboratory and seedling emergence following autumn sowing. Seeds in which oil was the major seed storage component were more short lived, whereas carbohydrates or proteins did not show an effect on seed longevity.

Historic collections of biological material are important genetic resources for taxonomic, evolutionary and historical research. In this paper we describe a seed collection dating from 1862 to 1918 maintained at the Swedish Museum of Cultural History. The collection contains over 3000 well-documented seed samples of various agricultural crops, mostly cereals. A subset of 100 samples divided over ten species frequently represented in the collection and a range of ages were tested for germinability and DNA preservation. None of these accessions were found to contain viable seeds. DNA extracted from the seeds was degraded, but the amount of degradation varied between species. DNA quality was evaluated by yield, fragment size and size of amplification product. Quality was highest for DNA extracted from Pisum sativum and Vicia sativa. DNA extracted from Brassica napus, Beta vulgaris and Trifolium pratense was more fragmented, and DNA extracted from Triticum aestivum, Secale sereale, Hordeum vulgare, Avena sativa and Phleum pratense was most degraded. Polymerase chain reaction (PCR) amplification of ribosomal DNA fragments of up to 700 bp was permitted for most samples in all species. To test whether single-copy nuclear genes could be amplified from the extracted DNA, microsatellite markers were used on the Pisum sativum and Hordeum vulgare samples. Polymorphisms of microsatellite markers were detected between samples for both species. The results show that the 19th-century seed collection can be utilized to infer genetic relationships among obsolete cultivars as well as for other types of genetic research based on sequence or marker analysis.

Efficient seed storage is a shared concern among the growing number of seed banks established for crop improvement or ex situ conservation. Container properties greatly affect seed interactions with the environment and the overall cost and success of seed banking operations. Several material properties contribute to their suitability as seed containers. This paper provides a consolidated list of water vapour permeability properties of thermal plastics commonly used for packaging. Composite packages with layers of film with different properties provide distinct advantages to seed banks. Different seed banks must rank the importance of the various factors depending on their mission and resources. Once the risks, costs and benefits are weighed, an appropriate strategy can be developed that addresses a seed bank's specific needs. Because there are many problems and several solutions, it is likely that strategies will vary among seed banks. This response details variables to consider when selecting seed storage packages, and focuses on water diffusion rates of packages with different compositions. A ‘moisture audit’ will help seed bank operators make informed decisions about packaging.

Seeds of different species are believed to have characteristic shelf lives, although data confirming this are scarce, and a mechanistic understanding of why this should be remains elusive. We have quantified storage performance of c. 42,000 seed accessions, representing 276 species, within the USDA National Plant Germplasm System (NPGS) collection, as well as a smaller experiment of 207 cultivars from 42 species. Accessions from the NPGS collection were harvested between 1934 and 1975, and had relatively high initial germination percentages that decreased at a variable rate during storage at both 5 and –18°C. Germination time courses, which represent the average performance of the species, were fitted to Avrami kinetics, to calculate the time at which germination characteristically declined to 50% (P50). These P50 values correlated with other longevity surveys reported in the literature for seeds stored under controlled conditions, but there was no correlation among these studies and seed persistence observed in the classic buried seed experiment by Duvel. Some plant families had characteristically short-lived (e.g. Apiaceae and Brassicaceae) or long-lived (e.g. Malvaceae and Chenopodiaceae) seeds. Also, seeds from species that originated from particular localities had characteristically short (e.g. Europe) or long (e.g. South Asia and Australia) shelf lives. However, there appeared to be no correlation between longevity and dry matter reserves, soluble carbohydrates and parameters relating to soil persistence or resource allocation. Although data from this survey support the hypothesis that some species tend to survive longer than others in a genebank environment, there is little information on the attributes of the seed that affect its storage performance.

In response to the rapid loss of animal genetic resources, a world wide emergency program is proposed to create national genebanks on the basis of somatic cells. Contrary to other procedures, like storing deep frozen semen or embryos, collection and storage of somatic cells can be done cheaply and rapidly for any species. Only in this way can an emergency store of animal genetic resources be created fast enough to forestall the ongoing rapid erosion of animal biodiversity. While animals can already be produced from somatic cells for 10 species, this number will continue to rise in the future. A layered strategy is proposed which is based on collection and storage within individual countries, thus leaving execution of the program, responsibility and ownership of these national cryobanks with those countries. After a pilot study, more country genebanks could be created as funds become available. With a limited effort, the creation of a network of national genebanks of last resort are a realistic option.